EFFECT OF LIDOCAINE SOLID LIPID NANOPARTICLES ON SCIATIC NERVE BLOCK ON RATS

WeiLi, Hua Zhong, Liang Zhang^*

Department of Anesthesiology, Gongan County People’s Hospital

Objective: To prepare PLGA magnetic nanoparticles loaded with rat nerve growth factor (mNGF) and evaluate their release behavior in vitro. MRI was used to study the aggregation of magnetic nanoparticles in the injured area of left sciatic nerve after injury. 

Methods: Magnetic MNCF PLGA nanoparticles were prepared by phacoemulsification with mNGF as model drug. The nanoparticles were characterized by transmission electron microscope and laser particle size analyzer. The standard curve of MNCF was drawn by enzyme-linked immunosorbent assay (ELSA). The encapsulation efficiency, drug loading and in vitro release were measured. The model of sciatic nerve injury was made in SD rats. Magnetic mngf-plga nanoparticles were injected into the tail vein of SD rats. The T2 values of the left and right lower limbs were recorded. 

Results: The magnetic mngf-plga sample was a brown suspension with uniform size, average particle size of (205.9±1.2) mm and uniform particle size distribution. Transmission electron microscopy confirmed that the nanoparticles were spherical in shape, which contained a large number of mNGF. The drug encapsulation rate and drug loading rate were (69.43±2.80)% and (3.11±3.27)% respectively. In vitro release experiments showed that magnetic mncf-plga nanoparticles sustained release mNGF, the first 12 hours release rate was 30%, the fifth day cumulative release rate was 92%. MRI imaging showed that T2 values of left and right lower limbs were higher before injection, 312.68 and 314.74, respectively. After injection, T2 values decreased, but the difference between left and right values was not obvious, 264.43 and 263.78, respectively. After 2 hours of external magnetic field guidance, T2 value further decreased, and the left leg was significantly lower than the right leg, 150.90 and 233.54 respectively. 

Conclusion: 1) magnetic mngfpga nanoparticles with small particle size, narrow distribution, high encapsulation efficiency and drug loading rate can be prepared by single emulsion solvent evaporation method. 2) The magnetic nanoparticles have good release effect in vitro, controllable and long sustained release effect. 3) PLCA magnetic nanoparticles loaded with mNGF can effectively reduce T2 value and have obvious aggregation under external magnetic field, which is a good basis for further study of magnetic targeted repair of peripheral nerve injury.